Muglad盆地Unity凹陷及邻区AG2段沉积相与沉积模式分析

Sedimentary facies and model of second member of AG Formation,Unity Sag and adjacent area in Muglad Basin

通过研究沉积相与沉积模式,明确有利砂体展布特征对岩性—地层油气藏勘探具有重要意义。Muglad盆地Unity凹陷Abu Gabra组2段(简称AG2,下同)沉积特征及平面展布尚不明确,制约着岩性—地层油气藏的勘探工作。本文针对该问题,综合利用测井、录井、地震等资料,运用经典层序地层学理论以及构造演化分析,揭示了Unity凹陷AG2段沉积特征并建立了辫状河三角洲—湖泊沉积模式。研究结果表明:研究区AG2段的物源区为东部Toor凸起,凹陷内主要发育三角洲相及湖泊相,凹陷东部边缘发育冲积扇相;三角洲相、冲积扇相发育区均可成为有利的岩性地层油气藏勘探区。研究成果可为Unity凹陷岩性—地层油气藏有利区带优选提供科学依据。

Study on sedimentary facies and sedimentary model play an important role in determining the distribution characteristics of favorable sand bodies for the exploration of lithologic-stratigraphic reservoirs. Applying the classical sequence stratigraphy theory and tectonic evolution analysis based on mud logging, wireline logging and seismic data in this paper, the research on the sedimentary features and distribution of AG2 member of Unity Sag in Muglad Basin is carried out. Result shows that the AG2 Member in Unity Sag is deposited in the braided river delta-lacustrine environment. Toor uplift in eastern slope region is the main provenance, where braided delta and lacustrine facies are developed in the the study area. In addition, alluvial fan is deposited on the eastern margin of the sag. The delta facies and alluvial fan are the favorable areas of lithologic-stratigraphic reservoirs. The research results can give understanding basis for favorable exploration areas of lithologic-stratigraphic reservoirs.